Flexible display device and method of manufacturing the same

ABSTRACT

A flexible display device and a method of manufacturing the same are provided. The flexible display device comprises a first flexible substrate including a display area including an organic light emitting layer, and a peripheral circuit area, and a second flexible substrate coming in contact with the first flexible substrate and including a pattern for facilitating bending thereof, wherein the second flexible substrate has a certain shape according to the pattern, and the first flexible substrate has a shape corresponding to the certain shape. Various embodiments of the present invention provide a flexible display device capable of realizing a narrow bezel-type or bezel-free display device and simultaneously realizing improved types of design, facilitating bending of a bezel area so as to realize a narrow bezel-type or bezel-free display device, and minimizing damage to an area to be bent.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 2012-0155873, filed on Dec. 28, 2012, the disclosure ofwhich is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a flexible display device, and moreparticularly to a narrow bezel or a bezel-free flexible display deviceand a method of manufacturing the same.

2. Discussion of Related Art

Display devices used in monitors of computers, TVs, and cell phonesinclude organic light emitting display devices (OLEDs) and plasmadisplay panels (PDPs), both of which autonomously emit light, and liquidcrystal display devices (LCDs) requiring a separate light source, etc.

In recent years, flexible display devices manufactured using materialsexhibiting inflexibility, such as flexible materials (i.e., plastics),to display an image even when bent like paper have received attention asnext-generation display devices.

Flexible display devices have been widely used in the field ofapplications spanning from monitors of computers and TVs to personalportable equipment, and research on flexible display devices having alarge display area and a smaller volume and weight has been conducted.

Various kinds of highly complicated technology, such as wirepositioning, line width setting, and signal transfer, are required torealize a narrow bezel.

SUMMARY OF THE INVENTION

Embodiment relate to a flexible display device including a flexibledisplay substrate and a support substrate. The flexible displaysubstrate includes a display area and a peripheral circuit area. Thedisplay area is formed with pixel elements for generating an image. Theperipheral circuit area includes components to transmitting signals tothe pixel elements in the display area. A support substrate is attachedto the flexible display substrate to provide rigidity to the flexibledisplay device. The support substrate includes a non-bending area, and abending area. The bending area extends along a boundary of theperipheral circuit area and the bending area, the bending area adjacentto the non-bending area, the bending area less rigid than thenon-bending area.

In one embodiment, thin film transistors are formed as the pixelelements on the flexible display substrate. The thin film transistorsoperate light emitting elements formed on the flexible display substratebased on the transmitted signals.

In one embodiment, the bending area is formed with a plurality of holes,a slit extending across the bending area or a half-cut channel.

In one embodiment, the half-cut channel is a hollow channel with anopening facing towards the flexible display substrate or facing awayfrom the flexible display substrate.

In one embodiment, the flexible display device further includes a coverglass having a display region corresponding to the display area of theflexible display substrate.

In one embodiment, the flexible display substrate is bent at asubstantially right angle along the bending area.

In one embodiment, the flexible display device further includes apolarizer on the flexible display substrate. The polarizer is formedwith a pattern along the bending area to provide flexibility to thepolarizer in the bending area.

In one embodiment, the flexible display device further includes a metalsubstrate interposed between the flexible display substrate and thesupport substrate.

In one embodiment, the flexible display device further includes anencapsulation layer extending over at least a portion of the displayarea and at least a portion of the peripheral circuit area.

In one embodiment, the flexible display device further includes a layeron the components for transmitting the signals in the peripheral circuitarea to reduce tensile stress in the components when bending occurs inthe bending area.

Embodiments also relate to a flexible display device that includes aflexible display substrate and a support substrate disposed on theflexible display substrate. The flexible display substrate has a displayarea and a peripheral circuit area. The display area is juxtaposed to aperipheral circuit area. A support substrate is disposed on the flexibledisplay substrate. The support substrate has a bending pattern toprovide flexibility at a bending area of the support substrate and toreduce resilient force of the flexible display device. The bending areacorresponds to a boundary between the display area and the peripheralcircuit area of the flexible display substrate.

In one embodiment, the bending pattern is a plurality of holes spacedapart from each other by a predetermined distance.

In one embodiment, a bending angle between the display area and theperipheral circuit area is between 70 degrees and 110 degrees.

Embodiments also relate to a multi-layered substrate structure includinga first flexible substrate, and a second flexible substrate. The secondflexible substrate is fixed to the first flexible substrate and is morerigid than the first flexible substrate. The second flexible substrateis formed with a bending pattern to define a bending area along whichthe multi-layered substrate structure is bent. An organic light emittingelement is also placed on the first flexible substrate of themulti-layered substrate structure.

In one embodiment, the bending pattern is formed along a boundarybetween a display area and a peripheral circuit area of the secondflexible substrate.

In one embodiment, the multi-layered substrate structure is formed withat least another bending pattern at an end portion of the secondflexible substrate.

In one embodiment, the multi-layered substrate structure includes atleast two separated display areas of the first flexible substrate. Thebending pattern is formed in a boundary of the at least two separateddisplay areas.

In one embodiment, at least one display area is placed between thebending pattern and the other bending pattern.

In one embodiment, the bending pattern includes a plurality of holesaligned along the boundary between a display area and a peripheralcircuit area of the multi-layered substrate structure.

In one embodiment, the bending pattern includes a half-cut channel onone surface of the second flexible substrate facing the first flexibledisplay substrate or facing away from the first flexible displaysubstrate.

In one embodiment, the multi-layered substrate structure is bent at asubstantially right angle along the bending area and the organic lightemitting element remains substantially planar.

Embodiments also relate to a flexible display device including aflexible display substrate and a plurality of support substrate. Theflexible display substrate includes a plurality of display areas. Eachof the display areas formed with pixel elements for generating an image.The support substrates are more rigid than the flexible displaysubstrate, each of the support substrate fixed to a selected portion ofthe flexible display substrate to maintain the selected portion of theflexible substrate in a planar shape. The flexible display substrate isbent at a bending area not fixed with the at least one supportsubstrates.

In one embodiment, the selected portion corresponds to one of thedisplay areas of the flexible display substrate and the bending areaincludes a non-display area for transmitting signals to the one of thedisplay areas.

In one embodiment, the flexible display substrate includes a firstportion fixed with a first support substrate, a second portion fixedwith a second support substrate, and a third portion fixed with a thirdsupport substrate. A first bending portion is formed between the firstportion and the second portion, and a second bending portion is formedbetween the second portion and the third portion.

In one embodiment, each of at least two adjacent support substrates hasa side end, which is not perpendicular to the corresponding portion ofthe flexible display substrate. Instead, the side end of at least twoadjacent support substrates is angled so that the gap between the twoadjacent support substrates is reduced upon bending of the flexiblesubstrate.

It is to be understood that both the foregoing general description andthe following detailed description are and explanatory and are intendedto provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which constitute a part of thisspecification, illustrate various embodiments of the present invention.

FIG. 1A is a top view of a flexible display device according to anembodiment of the present invention.

FIG. 1B is a cross-sectional view of the flexible display device takenalong the line Ib-Ib′ of FIG. 1A.

FIGS. 1C to 1I are cross-sectional views of flexible display devicesaccording to various embodiments of the present invention.

FIG. 2A is a top view of a support film used to illustrate the flexibledisplay device according to an embodiment of the present invention.

FIG. 2B is a cross-sectional view of the flexible display device takenalong the line IIb-IIb′ of FIG. 2A.

FIGS. 2C and 2D are cross-sectional views of the flexible display deviceof FIG. 2B in a bent state.

FIG. 2E is a top view of a support film used to illustrate the flexibledisplay device according to an embodiment of the present invention.

FIG. 2F is a cross-sectional view of the flexible display device takenalong the line IIf-IIf′ of FIG. 2E.

FIG. 2G is a cross-sectional view illustrating the flexible displaydevice of FIG. 2F in a bent state.

FIG. 2H is a cross-sectional view of a flexible display device accordingto an embodiment of the present invention.

FIG. 2I is a cross-sectional view showing the flexible display device ofFIG. 2H in a bent state.

FIG. 2J is a top view of the support film used to illustrate theflexible display device according to an embodiment of the presentinvention.

FIGS. 2K and 2L are cross-sectional views of flexible display devicesaccording to various embodiments of the present invention.

FIGS. 3A to 3D are cross-sectional views of flexible display devicesaccording to various embodiments of the present invention.

FIG. 4A is a cross-sectional view of a flexible display device accordingto an embodiment of the present invention.

FIG. 4B is a cross-sectional view showing the flexible display device ofFIG. 4A in a bent state.

FIGS. 4C and 4D are cross-sectional views of flexible display devicesaccording to various embodiments of the present invention.

FIG. 4E is a cross-sectional view showing the flexible display device ofFIG. 4D in a bent state.

FIG. 4F is a cross-sectional view of a flexible display device accordingto an embodiment of the present invention.

FIG. 4G is a cross-sectional view showing the flexible display device ofFIG. 4F in a bent state.

FIG. 5A is a top view of a support film used to illustrate the flexibledisplay device according to an embodiment of the present invention.

FIG. 5B is a cross-sectional view of the flexible display device takenalong the line Vb-Vb′ of FIG. 5A.

FIG. 6 is a flowchart illustrating an method for manufacturing anembodiment of flexible display.

FIGS. 7A to 7D are cross-sectional views illustrating an organic lightemitting display device at different steps of manufacturing a flexibledisplay device, according to one embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described in detail belowwith reference to the accompanying drawings. It is noted that thedrawings of the present application are provided for illustrativepurposes only and, as such, the drawings are not drawn to scale. In thefollowing description, numerous specific details are set forth, such asparticular structures, components, materials, dimensions, processingsteps and techniques, in order to provide an understanding of thevarious embodiments of the present disclosure. However, it will beappreciated by one of ordinary skill in the art that the variousembodiments of the present disclosure may be practiced without thesespecific details. In other instances, well-known structures orprocessing steps have not been described in detail in order to avoidobscuring the present disclosure.

It will be understood that when an element as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” another element, there are no intervening elements present.

It will also be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Further, it will be understood that when an element is referred to asbeing “overlapped” with another element, one element can be positionedabove the other element or below the other element. Moreover, althoughsome of the elements are designated with numerical terms (e.g., first,second, third, etc.), it should be understood that such designations areonly used to specify one element from a group of similar elements, butnot to limit the element in any specific order. As such, an elementdesignated as a first element could be termed as a second element or asthird element without departing from the scope of embodiments.

An organic light emitting display device described herein includes oneor more OLED elements. The OLED elements can be configured to operate inone of a top, bottom or dual emission mode, depending on the directionlight exiting the OLED elements. An OLED element is classified as bottomemission mode OLED element if the light emitted from the OLED elementpasses through a transparent or a semi-transparent bottom electrode andsubstrate on which the panel was manufactured. An OLED element isclassified as a top emission mode OLED element if the light emitted fromthe OLED element exits through a transparent or a semi-transparent topelectrode. An OLED element can be classified as a dual emission modeOLED element if the light emitted from the OLED element exits throughboth the top and bottom electrodes to emit light on both sides of theOLED element. The components of the organic light emitting displaydevice including, but not limited to, a thin film transistor, an anode,and a cathode as well as the structure of organic EL layer design, maybe configured differently based on the aforementioned emission modeswithout departing from the sprit of the present invention.

A flexible display device herein refers to a display device having somedegree of flexibility. The flexible display device herein is synonymouswith a bendable display device, a rollable display device, anunbreakable display device, or a foldable display device. As describedherein, a flexible organic light emitting display device is one exampleof various flexible display devices.

The flexible display device described in the present disclosure may betransparent. In the present disclosure, the terms “transparent” and“translucent” are used interchangeably to indicate property that lightat least partially passes through the flexible display device such thatobjects behind the display device is visible. Accordingly, a transparentdisplay device refers to a display device in which at least a part ofthe screen is transparent or semi-transparent so that the viewer is ableto see the content displayed by the device while still being able to seethe objects behind the display device in some degree.

The term “peripheral circuit area” described herein refers to an areawhere various circuits and wires are provide to transmit signals to theOLED. To increase the transparency of the flexible display device,non-transparent or opaque components of the display device (e.g.,battery, printed circuit board, metal frame), can be disposed in theperipheral circuit area rather than in the display/non-display displayareas.

The term “display area” is described herein refers to an area of theflexible display device where image is actually displayed. In case oftransparent flexible display device, the display area may include both apixel area and a non-pixel area. In such embodiment, the pixel area isconfigured to emit light for displaying image, while the non-pixel areais formed to be transparent so that external light can pass through thedisplay device.

Hereinafter, various embodiments of the present invention will bedescribed in further detail with reference to the accompanying drawings.

FIG. 1A is a top view of an flexible display device according to anembodiment of the present invention. FIG. 1B illustrates across-sectional view of the flexible display device, which is takenalong the line Ib-Ib′ of FIG. 1A. Referring to FIGS. 1A and 1B, theflexible display device 100 includes a multi-layered substrate structureformed of a support film 110 and a flexible substrate 120, a displayunit 130, a wire 165, and a drive circuit unit 170.

The flexible substrate 120 is a substrate configured to support variouselements of the flexible display device 100. The flexible substrate 120may also be referred to as a flexible substrate, a first flexiblesubstrate, or a flexible member. When the flexible substrate 120 isformed of a plastic, the flexible substrate 120 may be referred to as aplastic film, or a plastic substrate.

FIGS. 1A and 1B show that the flexible substrate 120 is in the form of aparallelopipedon. However, it should be noted that the flexiblesubstrate 120 can be formed in various other shapes.

The flexible substrate 120 is made of a flexible material. The flexiblesubstrate 120 may be made of material such as a polyester-based polymer,a silicone-based polymer, an acrylic polymer, a polyolefin-basedpolymer, and a copolymer thereof. More particularly, the flexiblesubstrate 120 may be made of material such as polyethylene terephthalate(PET), polybutylene terephthalate (PBT), polysilane, polysiloxane,polysilazane, polycarbosilane, polyacrylate, polymethacrylate,polymethylacrylate, polyethylacrylate, polyethylmetacrylate, a cyclicolefin copolymer (COC), a cyclic olefin polymer (COP), polyethylene(PE), polypropylene (PP), polyimide (PI), polymethylmetacrylate (PMMA),polystyrene (PS), polyacetal (POM), polyether ether ketone (PEEK),polyestersulfone (PES), polytetrafluoroethylene (PTFE),polyvinylchloride (PVC), polycarbonate (PC), polyvinylidenefluoride(PVDF), a perfluoroalkyl polymer (PFA), a styrene acrylonitrilecopolymer (SAN), and a combination thereof. The flexible substrate 120can also be formed of a transparent flexible material.

The flexible substrate 120 includes a display area “A” and a peripheralcircuit area “B”. The display area A of the flexible substrate 120refers to an area for displaying image, and the peripheral circuit areaB refers to an area where no image is displayed. The peripheral circuitarea B of the flexible substrate 120 may be positioned at one side ofthe display area A of the flexible substrate 120. Since the peripheralcircuit area B only contains wires and circuits and does not display anyimages therefrom, a protective member (e.g., housing, bezel) oftencovers the peripheral circuit area B. The peripheral circuit area B ofthe flexible substrate 120 may be formed in a polygonal shape, and theperipheral circuit area B of the flexible substrate 120 may include anarea extending from one side of the display area A of the flexiblesubstrate 120. Since the peripheral circuit area B of the flexiblesubstrate 120 is positioned at a peripheral or edge portion of thedisplay area A of the flexible substrate 120, the peripheral circuitarea B of the flexible substrate 120 may be referred to as a peripheralarea, an edge area, or a bezel area.

Such protective member is usually formed with a material havingsubstantially more rigidity than the flexible display device 100 andlimits the design of the flexible display device 100. Further, theprotective member makes the display device to stand out from thesurroundings, thereby making impedes immersive viewing experience to theviewers. Accordingly, it is advantageous to bend or curve the peripheralcircuit area B so that the bezel area for covering the peripheralcircuit area B can be reduced (i.e., narrow-bezel) or eliminated (i.e.,bezel-free). However, the support film 110 has much greater rigiditythan the flexible substrate 120. When the display area A is bent, stressmay be formed at or near the bend area of the display unit 130, causingthe display unit 130 or other components on the display unit 130 to peeloff from the flexible substrate 120.

A display unit 130 may extend partially or entirely over the displayarea A of the flexible substrate 120. The display unit 130 is acomponent that actually displays an image, and may be referred to as animage display unit or display panel. In some embodiments, display unit130 is embodied as an OLED that generates images by emitting light fromone or more organic light emitting layers.

Some or all of the elements of the display device that do not emit lightcan be disposed at the peripheral circuit area B of the flexiblesubstrate 120. The elements disposed at the peripheral circuit area B ofthe flexible substrate 120 may be connected to a drive circuit unit 170equipped within various ICs 175 (e.g., gate driver ICs or source driverICs), a wire 171, and a wire 165 electrically connecting the drivecircuit unit 170 to the display unit 130. The wire 165 electricallyconnects the display unit 130 disposed at the display area A to otherelements disposed at the peripheral circuit area B of the flexiblesubstrate 120. Therefore, part of the wire 165 may be disposed withinthe display area A of the flexible substrate 120. The drive circuit unit170 may be installed in the flexible substrate 120 using varioustechniques such as tape-carrier-package (TCP), chip-on-film (COF), andgate-in-panel (GIP) methods.

The support film 110 may come in contact with the flexible substrate 120and support the flexible substrate 120. The support film 110 may also bereferred to as a back film, a rear film, a second flexible substrate, ora protective film. In embodiments where the flexible substrate 120 isformed of a flexible plastic thin film, but flexible substrate 120 isvulnerable to external moisture and air. As a result, the display unit130 formed on the flexible substrate 120 may become damaged. Therefore,in the flexible display device 100 according to one embodiment of thepresent invention, the support film 110 may be disposed at a rearsurface of the flexible substrate 120 to reduce penetration of moistureand air to the display unit 130. The support film 110 may be formed ofsubstantially the same material as the flexible substrate 120, but maybe thicker than the flexible substrate 120.

The support film 110 includes a non-bending area and a bending areaformed with a bending pattern 111 to reduce rigidity of the support film110 in the corresponding areas. That is, the bending area of the supportfilm 110 formed with the bending pattern 111 is more flexible than othernon-bending areas of the support film 110, and hence, the bending can belocalized to bending area formed with the bending pattern 111. Becausethe support film 110 can be bent along the bending area formed with thebending pattern 111, the flexible substrate 120 and the supportsubstrate 110 can remain fixed even after the bending of the flexibledisplay device 100.

In the example of FIGS. 1A and 1B, the bending pattern 111 is formedalong the boundary between the display area A and the peripheral circuitarea B to afford flexibility to the support substrate 110 in the bendingarea along the boundary. As shown in FIG. 1A, the bending pattern 111includes a plurality of through-holes in the support film 110. Althoughthe through-holes are shown as having an oval section, the openings canbe formed in various other shapes (e.g., a square and triangle) and invarious sizes.

The bending area formed with the bending pattern 111 may be centered atthe boundary between the display area A and the peripheral circuit areaB of the flexible substrate 120. In some embodiments, center of thebending area may be slightly offset towards the peripheral circuit areaB so that the bending of the flexible substrate 120 and the support film110 does not affect the display unit 130. The bending pattern 111 mayalso be in the form of a plurality of rows, at or near the boundarybetween the display area A and the peripheral circuit area B of theflexible substrate 120.

FIGS. 1C to 1F are cross-sectional views of flexible display devicesaccording to various embodiments of the present invention. In FIGS. 1Cto 1F, the embodiments as shown in FIGS. 1C to 1F are distinguished byadding letters to the ends of reference numerals used in FIGS. 1A and1B. However, the elements shown in FIGS. 1C to 1F are substantiallyidentical to the elements shown in FIGS. 1A and 1B, which have the samenumerals except for the letters in the corresponding reference numerals.

Referring to FIG. 1C, first, a bending pattern 111C may include a viahole formed through top and bottom surfaces of a support film 110C. Thevia hole may be formed in various shapes such as a cylindrical shape, apolyprismatic shape, etc., and a size of the via hole may be determinedaccording to various designs.

The bending pattern 111C may be formed in a bending area using variousstitching processes in which holes such as a via hole may be formed inthe support film 110C. As the various stitching processes for formingthe bending pattern 111C, laser processes and mechanical processes suchas a piercing process, a punching process and a press process may beused.

Referring to FIG. 1D, a bending pattern 111D can be formed as a half-cutchannel in a bending area having an opening that faces away from theflexible display substrate 120D. In other words, the bending pattern111D is a hollow space formed along the boundary of the display area Aand the peripheral circuit area B, in which the hollow space has limiteddepth that does not penetrate through the support film 111D. Althoughthe half-cut channel has a cross-sectional shape of a wedge in FIG. 1D,the half-cut channel can have other cross-sectional shapes such as acone shape, a polypyramid shape, a cylinder, a polyprismatic shape, andthe likes. Further, the opening size of the half-cut channel as well asthe depth of the half-cut channel through the support film 110D can varyaccording to the degree of flexibility desired at the bending pattern.

The flexibility of the support film 110D is increased as the supportfilm 110D is partially carved out along the boundary between the displayarea A and the peripheral circuit area B. Also, the support film 110Dremaining in the bending area (after forming the bending pattern 111D)functions as a hinge for bending the flexible display device 100D.Accordingly, when the half-cut channel has its opening on the bottomsurface of the support film 110D, the support film 110D and the flexiblesubstrate 120D can be bent or curved more easily towards the bottomsurface of the support film 110D having the hollow channel formedtherein.

As shown in FIG. 1E, in some other embodiments, the half-cut channel111E can be formed in the support film 110E in such a way that itsopening faces the flexible display substrate 120E. In suchconfigurations, the support film 110E and the flexible substrate 120Emay be bent inward toward a bottom surface of the support film 110E inwhich a groove is not formed.

FIG. 1F illustrates yet another type of bending pattern 111F, which canbe employed in various embodiments of the present invention. As shown,the support film 110F can be carved out to form a recessed region (i.e.,bending pattern 111F) in a bending area along the boundary of thedisplay area A and the peripheral circuit area B. In FIG. 1F, thesupport film 110F is cutout, or otherwise carved out, in a rectangularshaped cross-section to create a rectangular channel shaped recess alongthe boundary of the display area A and the peripheral circuit area B. Itshould be understood that the support film 110F can be cutout in variousother shapes to form channels having different shapes. For instance, thecutout in the support film 110F can be in a rounded shape so that therecession along the boundary has a semi-circular channel shape. Similarto the half-cut channel described above, the recessed region (e.g.,bending pattern 111F) may be formed on a top and/or bottom surface ofthe support film 110F to facilitate bending of the flexible displaydevice in the both directions. Depending on the degree of flexibilityrequired by the flexible display device 100F, the dimension of cutout(i.e., the volume of the support film 110F removed therefrom) along theboundary as well as the shape of the cutout can vary.

The bending patterns 111D, 111E and 111F may be formed in the bendingarea using a variety of methods capable of cutting out, or otherwisecarving out, the support substrate. For instance, the support substratecan be carved out in a desired shape and size (e.g., depth, width,length) by using laser and/or mechanical tools. Such tools can beemployed to conduct various processes, including but not limited to, apiercing process, a punching process and a press process to half-cut thesupport film according to the desired specification.

In the embodiments described herein, the bending patterns areillustrated as being formed in a bending area of the support film alongthe boundary between the display area A and the peripheral circuit areaB. However, it should be noted that the bending pattern can be formed ata boundary between two adjacent but distinct display areas of theflexible display device. For example, a flexible display device mayinclude two immediately adjacent display areas disposed next to aperipheral circuit area, and the bending patterns can be formed alongthe boundary between the two immediately adjacent display areas as wellas the boundary between the juxtaposed adjacent display areas and theperipheral circuit area.

Further, each of the bending pattern types 111C, 111D, 111E and 111F aredescribed herein as being formed in a discrete flexible display device.Some embodiments of the flexible display device may employ multipletypes of the bending patterns described herein. For instance, a flexibledisplay device may include a plurality of bending patterns formed on thesupport substrate, and one bending patterns can be formed with aplurality of holes and while another bending patterns is formed as ahalf-cut channel and/or recessed region described above. In someembodiments, one layer of the flexible display device (e.g., flexibledisplay substrate 120) might be configured with one type of bendingpattern, while another layer of the flexible display device (e.g.,polarizer) is configured with different type(s) of bending pattern.

FIG. 1G is a cross-sectional view of a flexible display device accordingto another embodiment. The elements shown in FIGS. 1C and 1G aresubstantially identical to each other when the elements have the samenumerals other than the alphabet characters in the correspondingreference numerals, and thus repeated description of the elements isomitted herein for the sake of brevity. Referring to FIG. 1G, apolarizer 150G coming in contact with a flexible substrate 120G andcovering a display area A of the flexible substrate 120G is disposed.The polarizer 150G may be referred to as a polarizer film. In the casewhere display unit 130G is an organic light emitting diode, a contrastratio (CR) is markedly degraded when an external light incident from theoutside is reflected on a metal electrode or a wire of the organic lightemitting diode. In the flexible display device 100G according to anotherembodiment of the present invention, degradation of the contrast ratiocaused by reflection of external light may be prevented by disposing thepolarizer 150G on the flexible substrate 120G of the flexible substrate120G, that is, the display unit 130G. Also, the polarizer 150G may beformed only on the display area A of the flexible substrate 120G toreduce peeling of the polarizer 150G when a peripheral circuit area B ofthe flexible substrate 120G is bent.

FIG. 1H is a cross-sectional view of a flexible display device accordingto still another embodiment of the present invention. The elements shownin FIGS. 1G and 1H are substantially identical to each other when theelements have the same numerals other than the alphabet characters inthe corresponding reference numerals, and thus repeated description ofthe elements is omitted herein for the sake of brevity. A polarizer 150Hcoming in contact with a flexible substrate 120H and covering a displayarea A of the flexible substrate 120H and at least a part of aperipheral circuit area B of the flexible substrate 120H is disposed.The polarizer 150H includes a pattern 151H for facilitating bendingthereof, and the pattern 151H may be formed in a bending area of thepolarizer 150H along the boundary between the display area A and theperipheral circuit area B of the flexible substrate 120H to facilitatebending of the polarizer 150H, the flexible substrate 120H and thesupport film 110H, particularly, to facilitate bending of the polarizer150H, the flexible substrate 120H and the support film 110H with respectto the boundary between the display area A and the peripheral circuitarea B.

The bending pattern 111H for facilitating the bending of the supportfilm 110H is formed in the bending area where the pattern 151H are alsoformed to facilitate the bending of the polarizer 150H. That is, boththe pattern 151H and the bending pattern 111H may be formed in thebending area along the boundary between the display area A and theperipheral circuit area B of the flexible substrate 120H. The pattern151H and the bending pattern 111H may be formed in the same or differentshapes. The pattern 151H and the bending pattern 111H may facilitate thebending of the polarizer 150H, the flexible substrate 120H and thesupport film 110H, particularly, facilitate the bending of the polarizer150H, the flexible substrate 120H and the support film 110H with respectto the boundary between the display area A and the peripheral circuitarea B.

As briefly mentioned above, the flexible display device 100H may includetwo display areas that are immediately adjacent to each other, and thebending patterns 111H and 151H can be formed at or near the boundarybetween the two immediately adjacent display areas. Moreover, thebending pattern 111H formed on the support film 110H may differ from thebending pattern 151H formed on the polarizer 150H.

FIG. 1I is a cross-sectional view of a flexible display device 100Iaccording to yet another embodiment. The elements shown in FIGS. 1C and1I are substantially identical to each other when the elements have thesame numerals other than the alphabet characters in the correspondingreference numerals, and thus repeated description of the elements isomitted herein for the sake of brevity. Referring to FIG. 1I, a cover140I serves to protect a flexible display device 100I from externalmoisture, air and impact. Therefore, the cover 140I may be referred toas a lid or a cover member. The cover 140I may be formed of atransparent material since the cover 140I is disposed on a top surfaceof a flexible substrate 120I including a display unit 130I. The cover140I may be formed of a material having a high strength, such as glass,so as to improve a mechanical strength. When the cover 140I is formed ofglass, the cover 140I may be an injection-molded glass.

The cover 140I may have a first surface in contact with the flexiblesubstrate 120I including the display unit 130I and corresponding to atop surface of a first area of the flexible substrate 120I, and a secondsurface extending from the first surface. The first surface of the cover140I may extend along a plane parallel to the top surface of the displayarea A of the flexible substrate 120I, and the second surface of thecover 140I may extend along a plane that is not parallel to the topsurface of the display area A of the flexible substrate 120I butparallel to the surface of the flexible substrate 120I in the peripheralcircuit area B. The first and second surfaces of the cover 140I mayadjoin at various angles such as an acute angle, a right angle and anobtuse angle. Preferably, the first and second surfaces of the cover140I adjoin at an angle in the range of 70 degrees to 110 degrees.

When the first and second surfaces of the cover 140I adjoin at an acuteangle, a right angle or an obtuse angle, at least one section of thecover 140I may have a curved shape. For example, when the first andsecond surfaces of the cover 140I form a right angle as shown in FIG.1I, a section of the cover 140I may have a shape curved at a rightangle, and have a “┐”-shaped section. For ease of explanation, FIG. 1Ishows that the cover 140I has a shape curved at a right angle, but thepresent invention is not limited thereto. For example, the cover 140Imay have a shape curved at an acute angle or an obtuse angle, and may beformed in a curved shape having a non-linear section.

The flexible substrate 120I may be bent according to the shape of thecover 140I. The flexible substrate 120I, the display unit 130I and thesupport film 110I may be coupled with the cover 140I as shown in FIG.1I. While coupling the flexible substrate 120I, the display unit 130Iand the support film 110I with the cover 140I, the second area of theflexible substrate 120I and an area of the support film 110Icorresponding to the second area of the flexible substrate 120I may beguided and curved by the cover 140I, and the second area of the flexiblesubstrate 120I and an area of the support film 110I corresponding to thesecond area of the flexible substrate 120I may be positioned on planesdifferent from planes in which the first area of the flexible substrate120I and an area of the support film 110I corresponding to the secondarea of the flexible substrate 120I are placed, as shown in FIG. 1I.

The cover 140I and the flexible substrate 120I including the displayunit 130I may be attached to each other by means of a pressure-sensitiveadhesive member. When the pressure-sensitive adhesive member such as aphotocurable material or an optically clear adhesive (OCA) is disposedon the cover 140I or the flexible substrate 120I including the displayunit 130I, and the cover 140I is coupled with the flexible substrate120I, the display unit 130I and the support film 110I, the cover 140Imay be coupled with the flexible substrate 120I, the display unit 130Iand the support film 110I by means of the pressure-sensitive adhesivemember.

The cover 140I may include a touch screen panel. The cover 140I may beformed on the first area of the flexible substrate 120I on which thedisplay unit 130I is disposed. Therefore, an image generated on thedisplay unit 130I may be viewed through the cover 140I, and the cover140I may include a touch screen panel to accommodate an input by touchof a user.

FIG. 2A is a top view of a support film used to illustrate the flexibledisplay device according to an embodiment. FIG. 2B is a cross-sectionalview of the flexible display device according to another embodiment ofthe present invention, taken along the line IIb-IIb′ of FIG. 2A.Referring to FIGS. 2A and 2B, a flexible display device 200A includesmulti-layered substrate structure having a support film 210A and aflexible substrate 220A. Also included in the flexible display device200A is a display unit 230A.

The flexible substrate 220A is a substrate configured to support variouselements such as a flexible display device 200A. The flexible substrate220A may also be referred to as a flexible substrate, a first flexiblesubstrate, or a flexible member. When the flexible substrate 220A isformed of a plastic, the flexible substrate 220A may also be referred toas a plastic film, or a plastic substrate. The flexible substrate 220Amay be formed of a flexible material, for example, may be in the form ofa film made of materials such as a polyester-based polymer, asilicone-based polymer, an acrylic polymer, a polyolefin-based polymer,and a copolymer thereof. The flexible substrate 220A includes a displayarea A and a peripheral circuit area B. The display area A of theflexible substrate 220A refers to a display area, that is, an area onwhich an image is actually displayed. The peripheral circuit area B ofthe flexible substrate 220A refers to a non-display area, that is, anarea on which no image displayed. The flexible substrate 220A issubstantially identical to the flexible substrate 120C shown in FIG. 1C,and thus repeated description of the flexible substrate 120C is omittedfor brevity.

The support film 210A is in contact with the flexible substrate 220A.One surface of the flexible substrate 220A on which the display unit230A is disposed is referred to as a top surface or a front surface ofthe flexible substrate 220A while the other surface of the flexiblesubstrate 220A coming in contact with the support film 210A may bereferred to as a bottom surface or a rear surface of the flexiblesubstrate 220A. The support film 210A may be referred to as a back film,a rear film, a second flexible substrate, or a protective film.

The support film 210A serves to support the flexible substrate 220A. Theflexible substrate 220A may be in the form of a flexible plastic thinfilm. Since this plastic film is vulnerable to external moisture andair, a display unit 230A formed on the flexible substrate 220A may bedamaged if exposed to the external moisture and air. Therefore, in theflexible display device 200A according to one embodiment, the supportfilm 210A may be disposed at a rear surface of the flexible substrate220A to reduce the damage of the elements such as a display unit 230Adue to the penetration of external moisture and air. The support film210A may be formed of substantially the same material as the flexiblesubstrate 220A, but may be thicker than the flexible substrate 220A.

The support film 210A includes a bending area formed with a pattern 211Awhere the bending of the flexible substrate is localized. Bending ofvarious elements included in the flexible display device 200A may belocalized at or near the pattern 211A without affecting the display areaA. The pattern 211A may also be referred to as an easily crookableshape, an easily bendable shape, a bendable print, or a bending line.The pattern 211A is substantially identical to the patterns 111C, 111D,111E and 111F shown with reference to FIGS. 1C to 1F, and thus repeateddescription of the pattern 211A is omitted herein for the sake ofbrevity.

FIGS. 2C and 2D are cross-sectional views of the flexible display deviceof FIG. 2B in a bent state, according to one embodiment. Referring toFIGS. 2C and 2D, the shape of the flexible substrate 220A is determinedby the shape of the support film 210A. More particularly, the shape ofthe flexible substrate 220A is determined by the shape of a sectionalprofile of the support film 210A. Since the flexible substrate 220A is aflexible plastic thin film, the shape of the flexible substrate 220A isrelatively flexible and the flexible substrate 220A may not maintain itsshape without any supporting structure. On the other hand, since thesupport film 210A is thicker than the flexible substrate 220A and morerigid, it is relatively easy to maintain the shape of the support film210A. Therefore, the shape of the flexible substrate 220A disposed onthe support film 210A is determined by the shape of the support film210A, and the flexible substrate 220A may also be bent in the same wayas the support film 210A.

Referring to FIG. 2D, the support film 210A has a certain shapeaccording to the pattern 211A, and the flexible substrate 220A has ashape corresponding to the certain shape of the support film 210A. Whenthe peripheral circuit area B of the flexible substrate 220A is crookedin a state in which the flexible substrate 220A is disposed on thesupport film 210A, the support film 210A and the flexible substrate 220Amay be bent with respect to the pattern 211A formed on the support film210A. FIG. 2D shows that the flexible substrate 220A and the supportfilm 210A are bent at a right angle, that is, bent in a “┐” shape, withrespect to the pattern 211A, but the present invention is not limitedthereto. For example, the support film 210A and the flexible substrate220A may be bent at various angles such as an acute angle and an obtuseangle with respect to the pattern 211A.

The support film 210A may have various sectional shapes. When anexternal force is applied to the support film 210A, the support film210A may have a “-” letter-shaped section. On the other hand, when anexternal force is applied to the support film 210A, the support film210A is bent at the boundary defined as the pattern 211A, and thus mayhave a curved shape or a curved state. For example, the support film210A may have a “┐”-shaped section. Also, when an external force isapplied to the support film 210A, the support film 210A may have anon-linear section. Here, the term “non-linear section” encompasses acase in which shapes other than a straight line are present in a sectionof the support film 210A, and may refer to a circular or curved sectionhaving a certain radius of curvature.

In some embodiments, the support film 210A may be bent at the boundarydefined as the pattern 211A, and the flexible substrate 220A having thedisplay unit 230A disposed thereon may then be attached to the bentsupport film 210A. That is, the support film 210A may be bent at theboundary defined as the pattern 211A into various shapes, and theflexible substrate 220A may then be attached to the bent support film210A. Therefore, a tension of the bent flexible substrate 220A may bedecreased. In some embodiments, to fix the bent support film 210A asnecessary, a double-sided adhesive tape may be used. In this case, theflexible substrate 220A may be attached to the support film 210A in abent state by means of the double-sided adhesive tape.

FIG. 2E is a top view of a support film used to illustrate the flexibledisplay device according to another embodiment of the present invention.FIG. 2F is a cross-sectional view of the flexible display deviceaccording to still another embodiment of the present invention, takenalong the line IIf-IIf′ of FIG. 2E. FIG. 2G is a cross-sectional viewshowing a bent state of the flexible display device shown in FIG. 2F.Referring to FIGS. 2E to 2G, a flexible display device 200B includes aflexible substrate 220B, a display unit 230B and a support film 210B.Among the elements of the flexible display device 200B, only the supportfilm 210B is shown in FIG. 2E for the sake of convenience ofdescription.

Referring to FIGS. 2E and 2F, the flexible substrate 220B includes adisplay area A and a peripheral circuit area B. The display area A ofthe flexible substrate 220B refers to a display area, that is, an areaon which an image is actually displayed, and the display unit 230B maybe disposed on the display area A of the flexible substrate 220B. Theperipheral circuit area B of the flexible substrate 220B may bepositioned at both sides of the first areas A of the flexible substrate220B. For the sake of convenience of description, FIG. 2E shows thatboth sides of the display area A of the flexible substrate 220B on whichthe peripheral circuit area B of the flexible substrate 220B ispositioned are indicated by both sides positioned opposite to thedisplay area A of the flexible substrate 220B, but the present inventionis not limited thereto. For example, both sides of the display area A ofthe flexible substrate 220B may be defined as both sides positionedclose to the display area A of the flexible substrate 220B. The flexiblesubstrate 220B is substantially identical to the flexible substrate 220Ashown in FIGS. 2A to 2D, except that the second areas B of the flexiblesubstrate 220B are positioned at both sides of the display area A of theflexible substrate 220B, and thus repeated description of the flexiblesubstrate 220B is omitted herein for the sake of brevity.

The support film 210B includes a bending pattern 211B for facilitatingbending thereof. The bending pattern 211B may include via holes, agroove or a combination thereof. The bending pattern 211B may be formedin an area of the support film 210B corresponding to the boundarybetween the display area A and the peripheral circuit area B of theflexible substrate 220B. The bending pattern 211B may be formed in anarea of the support film 210B at or near the boundary between thedisplay area A and the peripheral circuit area B of the flexiblesubstrate 220B so as to facilitate bending of the support film 210B andthe flexible substrate 220B disposed on the support film 210B. Moreparticularly, the bending pattern 211B may serve to facilitate thebending of the support film 210B and the flexible substrate 220B withrespect to the boundary between the display area A and the peripheralcircuit area B. As described above, since the peripheral circuit areas Bof the flexible substrate 220B are located at both sides of the displayarea A of the flexible substrate 220B, the patterns 211B may be formedin areas corresponding to the two boundaries between the display area Aand the peripheral circuit areas B of the flexible substrate 220B. Thesupport film 210B is substantially identical to the support film 210Ashown in FIGS. 2A to 2D, except that the patterns 211B of the supportfilm 210B are formed in the areas at or near the two boundaries betweenthe display area A and the peripheral circuit area B of the flexiblesubstrate 220B, and thus repeated description of the support film 210Bis omitted herein for the sake of brevity.

Referring to FIG. 2G, the support film 210B is bent according to thebending pattern 211B, and the flexible substrate 220B is also bent intoa shape corresponding to the curvature of the support film 210B. For thesake of convenience of description, FIG. 2G shows that the flexiblesubstrate 220B and the support film 210B are bent at a right angle, thatis, bent in a “┐” shape, with respect to the bending pattern 211B, butthe present invention is not limited thereto. For example, the supportfilm 210B and the flexible substrate 220B may be bent at various anglessuch as an acute angle and an obtuse angle with respect to the bendingpattern 211B. For the sake of convenience of description, FIG. 2G alsoshows that both of the second areas B of the flexible substrate 220B arebent according to the certain shape of the support film 210B, but thepresent invention is not limited thereto. For example, only one of theperipheral circuit areas B of the flexible substrate 220B may be bent.

FIG. 2H is a cross-sectional view of a flexible display device accordingto yet another embodiment. FIG. 2I is a cross-sectional view showing abent state of the flexible display device shown in FIG. 2H. A flexiblesubstrate 220C and a display unit 230C are substantially identical tothe flexible substrate 220B and the display unit 230B shown in FIGS. 2Eto 2G, and thus repeated description of the flexible substrate 220C andthe display unit 230C is omitted for brevity.

Referring to FIGS. 2H and 2I, a support film 210C has a size that issubstantially equal to the display area A of the flexible substrate220C, and a peripheral circuit areas B of the flexible substrate 220Care not supported by the support film 210C. As described above, thesupport film 210C is thicker than the flexible substrate 220C.Therefore, when the support film 210C is bent, an elastic restoringforce may be generated, it is difficult to maintain a bent state of thesupport film 210C, or a configuration of the display unit 230C or thepolarizer that may be disposed on the flexible substrate 220C may bepeeled off in a bent state. In the case of a flexible display device200C according to still another embodiment of the present invention, thesupport film 210C has a size corresponding to the display area A of theflexible substrate 220C on which the display unit 230C is disposed, andoverlaps only with the display area A of the flexible substrate 220C,and the peripheral circuit areas B of the flexible substrate 220C do nothave the support film 210C attached thereto. Therefore, even when theperipheral circuit areas B of the flexible substrate 220C are bent,there is no portion of the support film 210C that is bent along with theperipheral areas B of the flexible substrate 220. Therefore, peeling ofthe display unit 230C or the polarizer due to the bending of the supportfilm 210C may be prevented or reduced.

FIG. 2J is a top view of the support film used to illustrate theflexible display device according to still another embodiment of thepresent invention. Among the elements of the flexible display device,only a support film 210D is shown in FIG. 2J for the sake of convenienceof description.

Referring to FIG. 2J, the support film 210D includes two bendingpatterns 211D for facilitating bending thereof. In this example, each ofthe bending patterns 211D is formed with a plurality of via holes.

As previously described, however, each bending pattern 211D can bedifferent bending pattern type (e.g., a plurality of holes, half-cutchannel, recessed region). It should be appreciated that each of theplurality of via holes can have different shape and size depending onthe desired flexibility of the support film 210D. For example, some partof the flexible display device may be need additional flexibility thansome other parts of the flexible display device. As such, the bendingpattern disposed at the part requiring more flexibility may be formedwith more number of via holes or via holes having a larger size. Whenother types of the bending patterns are used, the part of the displaydevice requiring more flexibility may employ a half-cut channelpenetrating deeper (i.e., half-cut channel having larger depth) than thehalf-cut channel used in other parts of the display device. Likewise,larger area of the support film can be carved out at the part of thedisplay device requiring more flexibility.

The bending pattern 211D may be formed in an area of the support film210D corresponding to the boundary between a first area (e.g., displayarea or peripheral circuit area) and a second area (e.g., display areaor peripheral circuit area) of a flexible substrate 220D. The bendingpattern 211D may be formed in the area of the support film 210Dcorresponding to the boundary between the first area and the second areaof the flexible substrate 220D so as to facilitate bending of theflexible substrate 220D disposed on the support film 210D and thesupport film 210D. More particularly, the pattern 211D may serve tofacilitate bending of the support film 210D and the flexible substrate220D with respect to the boundary between the first area and the secondarea. As described above, since the second areas of the flexiblesubstrate 220D are positioned on both sides of the first area of theflexible substrate 220D, the patterns 211D may be formed in areascorresponding to the two boundaries between the first area and thesecond area of the flexible substrate 220D. The support film 210B issubstantially identical to the support film 210B shown in FIGS. 2E to2G, except that the patterns 211D are positioned at both sides of thesupport film 210D, and thus repeated description of the support film210B is omitted for brevity.

FIG. 2K is a cross-sectional view of a flexible display device accordingto an embodiment of the present invention. Referring to FIG. 2K, aflexible display device 200E includes a flexible substrate 220E, adisplay unit 230E, a metal thin film layer 260E and a support film 210E.The flexible substrate 220E, the display unit 230E and the support film210E are substantially identical to the flexible substrate 220B, thedisplay unit 230B and the support film 210B shown in FIG. 2F, and thusrepeated description of the flexible substrate 220E, the display unit230E and the support film 210E is omitted herein for the sake ofbrevity.

Referring to FIG. 2K, the metal thin film layer 260E is disposed betweenthe flexible substrate 220E and the support film 210E. That is, themetal thin film layer 260E is disposed on a rear surface of the flexiblesubstrate 220E, and the support film 210E is disposed on a rear surfaceof the metal thin film layer 260E. In the flexible display device 200Eaccording to yet another embodiment of the present invention, the metalthin film layer 260E may be disposed at the rear surface or a part ofthe rear surface of the flexible substrate 220E to reduce penetration ofmoisture or oxygen into the flexible substrate 220E. Also, since themetal thin film layer 260E has a characteristic effective forelectrostatic charge, the likelihood of damage of the metal thin filmlayer 260E caused by electrostatic discharge (ESD) may be reduced. Also,the material forming the metal thin film layer 260E can be chosen inconsideration of the thickness of the metal thin film layer 260E so thatthe metal thin film layer 260E does not excessively increase therigidity of the flexible display device. However, the material and thethickness of the metal thin film layer 260E may reduce the elastic forceto further facilitate bending of the flexible display device 200E.

FIG. 2L is a cross-sectional view of a flexible display device accordingto yet another embodiment of the present invention. Referring to FIG.2L, a flexible display device 200F includes a flexible substrate 220F, adisplay unit 230F, and a support film 210F. The flexible substrate 220Fand the display unit 230F are substantially identical to the flexiblesubstrate 220C and the display unit 230C shown in FIG. 2I, and thusrepeated description of the flexible substrate 220F and the display unit230F is omitted herein for the sake of brevity.

Referring to FIG. 2L, the support film 210F is formed of a moldableresin. In this case, lateral sides of the support film 210F may beformed with a curved shape. Here, the moldable resin means such asurethane or rubber may be used for the support film 210F. The supportfilm 210F can be formed using a method such as injection molding. Asshown in FIG. 2I, the flexible substrate 220F having the display unit230F formed thereon is attached on the support film 210F having a curvededge. In other words, the support film 210F may have a sufficientthickness and its lateral sides may be formed in a curved shape so thatthe edge portions of the display device can have a curved shape withoutbending the support film 210F. Therefore, a strain at the corner of theflexible substrate 220F may be reduced.

FIGS. 3A to 3C are cross-sectional views of flexible display devicesaccording to various embodiments. Referring to FIGS. 3A to 3C, patterns311A, 311B, 391B, 311C and 391C for facilitating bending are formed inat least one of protective layers 390A, 390B and 390C and support films310A, 310B and 310C.

First, referring to FIG. 3A, a flexible display device 300A includes aflexible substrate 320A, a display unit 330A, a support film 310A and aprotective layer 390A. In this case, a pattern 311A for facilitatingbending is formed in the support film 310A. The flexible substrate 320A,the display unit 330A and the support film 310A are substantiallyidentical to the flexible substrate 220B, the display unit 230B and thesupport film 210B shown in FIGS. 2E to 2G, and thus repeated descriptionof the flexible substrate 320A, the display unit 330A and the supportfilm 310A is omitted herein for the sake of brevity.

The protective layer 390A coming in contact with the flexible substrate320A and covering a display area A and a peripheral circuit area B ofthe flexible substrate 320A is disposed. The protective layer 390Aincludes a sealant 395A and a protective film 396A. The protective layer390A may be configured to be wider according to a method of sealinginternal elements of the flexible display device 300A. For example, amethod of sealing the flexible display device 300A includes thin filmencapsulation (TFE), face sealing, etc. As described herein, aprotective layer formed using a face sealing method favorable forflexible display applications among various sealing methods is used asthe protective layer 390A, but the present invention is not limitedthereto. The protective layer 390A may also be formed using otherencapsulation methods. The protective film 396A is glued onto thesealant 395A in the form of a thin film, and the protective film 396Aserves to protect the internal elements of the flexible display device300A. The protective film 396A may be formed of a flexible material, forexample, a plastic, a metal, a metal oxide, a ceramic oxide and apolymer material, or a combination of a plastic, a metal, a metal oxide,a ceramic oxide and/or a polymer material.

The sealant 395A in the protective layer 390A is formed at the displayarea A of the flexible substrate 320A, and the protective films 396A areformed at the display area A and the peripheral circuit area B of theflexible substrate 320A. The sealant 395A serves to seal the internalelements of the flexible display device 300A, especially the displayunit 330A. The sealant 395A is formed at the display area A of theflexible substrate 320A on which the display unit 330A is disposed. Thesealant 395A may be formed at the display area A of the flexiblesubstrate 320A. In some embodiments, however, the sealant 395A may alsobe formed at both the display area A and the peripheral circuit area Bof the flexible substrate 320A.

Next, referring to FIG. 3B, a flexible display device 300B includes aflexible substrate 320B, a display unit 330B, a support film 310B and aprotective layer 390B, and patterns 311B and 391B for facilitatingbending are formed in the support film 310B and the protective layer390B. The flexible substrate 320B, the display unit 330B and the supportfilm 310B are substantially identical to the flexible substrate 320A,the display unit 330A and the support film 310A shown in FIG. 3A, andthus repeated description of the flexible substrate 320B, the displayunit 330B and the support film 310B is omitted herein for the sake ofbrevity.

A pattern 391B is formed in an area of a protective film 396B of theprotective layer 390B corresponding to the boundary between a displayarea A and a peripheral circuit area B of the flexible substrate 320B.The pattern 391B may be formed in the area of the protective film 396Bof the protective layer 390B corresponding to the boundary between thedisplay area A and the peripheral circuit area B of the flexiblesubstrate 320B to facilitate bending of a polarizer 390B, the flexiblesubstrate 320B and the support film 310B, particularly, to localizebending of the protective layer 390B, the flexible substrate 320B andthe support film 310B with respect to the boundary between the displayarea A and the peripheral circuit area B.

Subsequently, referring to FIG. 3C, a flexible display device 300Cincludes a flexible substrate 320C, a display unit 330C, a support film310C, a polarizer 350C and a protective layer 390C, and patterns 311 and391C for facilitating bending are formed in the support film 310C andthe protective layer 390C. The flexible substrate 320C, the display unit330C, the support film 310C and the protective layer 390C aresubstantially identical to the flexible substrate 320B, the display unit330B, the support film 310B and the protective layer 390B shown in FIG.3B, and thus repeated description of the flexible substrate 320C, thedisplay unit 330C, the support film 310C and the protective layer 390Cis omitted herein for the sake of brevity.

The polarizer 350C in contact with the flexible substrate 320C andcovering a display area A of the flexible substrate 320C is disposed.The polarizer 350C may also be referred to as a polarizer film. In casewhere the display unit 330C is an organic light emitting diode, acontrast ratio (CR) is markedly degraded when an external light incidentfrom the outside is reflected on a metal electrode or a wire of theorganic light emitting diode. In the flexible display device 300Caccording to another embodiment of the present invention, degradation ofthe contrast ratio caused by reflection of external light may be reducedor eliminated by disposing the polarizer 350C on the display area A ofthe flexible substrate 320C, that is, the display unit 330C. Also, thepolarizer 350C may be formed only on the display area A of the flexiblesubstrate 320C to reduce or prevent peeling of the polarizer 350C when aperipheral circuit area B of the flexible substrate 320C is bent.

FIG. 3D is a cross-sectional view showing a bent state of the flexibledisplay device according to another embodiment. Referring to FIG. 3D, aflexible display device 300D includes a flexible substrate 320D, adisplay unit 330D, a support film 310D, a polarizer 350D, a protectivelayer 390D and a cover 340D. The flexible substrate 320D, the displayunit 330D, the support film 310D, the polarizer 350D and the protectivelayer 390D are substantially identical to the flexible substrate 320C,the display unit 330C, the support film 310C, the polarizer 350C and theprotective layer 390C shown in FIG. 3C, respectively, and thus repeateddescription of the above-described elements is omitted herein for thesake of brevity. Also, the cover 340D substantially identical to thecover 140I shown in FIG. 1I, and thus repeated description of the cover340D is omitted herein for the sake of brevity.

FIG. 4A is a cross-sectional view of a flexible display device accordingto another embodiment. FIG. 4B is a cross-sectional view showing a bentstate of the flexible display device shown in FIG. 4A. Referring toFIGS. 4A and 4B, a flexible display device 400A includes a support film410A, a flexible substrate 420B, a display unit 430B and a polarizer450B.

A flexible substrate 420A supports various elements of a flexibledisplay device 400A. The flexible substrate 420A may also be referred toas a flexible substrate, a first flexible substrate, or a flexiblemember. When the flexible substrate 420A is formed of a plastic, theflexible substrate 420A may be referred to as a plastic film, or aplastic substrate.

The flexible substrate 420A may be formed of a flexible material such asa polyester-based polymer, a silicone-based polymer, an acrylic polymer,a polyolefin-based polymer, and a copolymer thereof. More particularly,the flexible substrate 420A may be formed of polyethylene terephthalate(PET), polybutylene terephthalate (PBT), polysilane, polysiloxane,polysilazane, polycarbosilane, polyacrylate, polymethacrylate,polymethylacrylate, polyethylacrylate, polyethylmetacrylate, a cyclicolefin copolymer (COC), a cyclic olefin polymer (COP), polyethylene(PE), polypropylene (PP), polyimide (PI), polymethylmetacrylate (PMMA),polystyrene (PS), polyacetal (POM), polyether ether ketone (PEEK),polyestersulfone (PES), polytetrafluoroethylene (PTFE),polyvinylchloride (PVC), polycarbonate (PC), polyvinylidenefluoride(PVDF), a perfluoroalkyl polymer (PFA), a styrene acrylonitrilecopolymer (SAN), and a combination thereof. When the flexible displaydevice 400A is to be transparent, the flexible substrate 420A may beformed of a transparent flexible material.

The flexible substrate 420A includes a display area A, a peripheralcircuit area B and a third area C. The display area A of the flexiblesubstrate 420A refers to a display area, that is, an area on which animage is actually displayed. The peripheral circuit area B and the thirdarea C of the flexible substrate 420A refer to non-display areas, thatis, areas on which no image is displayed.

The peripheral circuit area B of the flexible substrate 420A is anon-display area which is positioned at the outermost area of theflexible substrate 420A. The peripheral circuit area B of the flexiblesubstrate 420A is positioned at an edge portion of the flexiblesubstrate 420A, and thus may also be referred to as an edge area or abezel area.

The third area C of the flexible substrate 420A is a non-display areawhich is positioned between the display area A and the peripheralcircuit area B of the flexible substrate 420A. The third area C of theflexible substrate 420A is positioned at a peripheral portion of thefirst area of the flexible substrate 420A, and positioned between thedisplay area A and the peripheral circuit area B of the flexiblesubstrate 420A, and thus may also be referred to as a peripheral area, amiddle area, or a bezel area.

A display unit 430A is disposed at all or part of the display area A ofthe flexible substrate 420A. The display unit 430A is an element foractually generating an image, and thus may be referred to as an imagedisplay unit 430A, or a display panel. The display unit 430A may be usedwithout limitation as long as it can be configured to display an image.It is described herein that the display unit 430A is an organic lightemitting diode for displaying an image through an organic light emittinglayer, and define that the image is displayed on an entire areacorresponding to the display unit 430A. A polarizer 450A capable ofimproving a contrast ratio is disposed on the display unit 430A.

The support film 410A serves to support the flexible substrate 420A. Asdescribed above, the flexible substrate 420A is in the form of aflexible plastic thin film. However, since this plastic film isvulnerable to penetration of moisture and air from the outside, there isa possibility of elements, such as a display unit 430A, formed on theflexible substrate 420A becoming damaged. Therefore, in the flexibledisplay device 400A according to still another embodiment of the presentinvention, the support film 410A may be disposed at a rear surface ofthe flexible substrate 420A to minimize damage of the elements such as adisplay unit 430A caused by the penetration of moisture and air from theoutside. The support film 410A may be formed of substantially the samematerial as the flexible substrate 420A, but have a relatively largerthickness than the flexible substrate 420A.

The support film 410A may be formed with a shape and size correspondingto those of the flexible substrate 420A. Since the support film 410Afunctions to support the flexible substrate 420A, the shape and size ofthe support film 410A may correspond to those of the flexible substrate420A, but the present invention is not limited thereto. For example, theshape and size of the flexible substrate 420A and the shape and size ofthe support film 410A may be determined in an independent manner.

The support film 410A includes a pattern 411A for facilitating bendingthereof. The pattern 411A for facilitating the bending may be referredto as a pattern 411A for facilitating bending of the support film 410A.As a result, bending of various elements included in the flexibledisplay device 400A may also be facilitated by facilitating the bendingof the support film 410A. The pattern 411A for facilitating the bendingmay also be referred to as an easily crookable shape, an easily bendableshape, a bendable print, or a bending line.

The pattern 411A may include at least one of a via hole and a groove ofthe support film 410A. The via hole and groove may be formed in variousshapes such as a cylindrical shape, a polyprismatic shape, a conicalshape, and a polypyramid shape, and the sizes of the via hole and groovemay be determined according to various designs.

The pattern 411A may be formed using various processes capable offorming a via hole or a groove in the support film 410A. As variousprocesses for forming the pattern 411A, laser processes and mechanicalprocesses such as a piercing process, a punching process, and a pressprocess may be used.

The pattern 411A may be formed in an area of the support film 410Acorresponding to the third area C between the display area A and theperipheral circuit area B of the flexible substrate 420A. The pattern411A may be formed in the area of the support film 410A corresponding tothe third area C of the flexible substrate 420A so as to facilitatebending of the support film 410A and the flexible substrate 420Adisposed on the support film 410A, particularly, to facilitate bendingof the support film 410A and the flexible substrate 420A with respect tothe third area C. For the sake of convenience of description, FIG. 4Ashows that the pattern 411A is formed in the third area C of theflexible substrate 420A in the form of one row, but the presentinvention is not limited thereto. For example, the pattern 411A may bein the form of a plurality of rows, and be irregularly formed in thethird area C of the flexible substrate 420A.

An area of the support film 410A corresponding to the display area A orthe peripheral circuit area B of the flexible substrate 420A may have ahigher average volume than an area of the support film 410Acorresponding to the third area C of the flexible substrate 420A. Asdescribed above, the pattern 411A is formed in the area of the supportfilm 410A corresponding to the third area C of the flexible substrate420A. Therefore, since a via hole or a groove is formed in the thirdarea C of the flexible substrate 420A, the area of the support film 410Acorresponding to the display area A or the peripheral circuit area B ofthe flexible substrate 420A may have a higher average than the area ofthe support film 410A corresponding to the third area C of the flexiblesubstrate 420A. In some embodiments, the area of the support film 410Acorresponding to the display area A or the peripheral circuit area B ofthe flexible substrate 420A may have a greater thickness than the areaof the support film 410A corresponding to the third area C of theflexible substrate 420A.

As described above, the display area A of the flexible substrate 420A isa display area on which an image is actually displayed, but theperipheral circuit area B of the flexible substrate 420A is anon-display area. Even if the peripheral circuit area B of the flexiblesubstrate 420A is positioned on the same plane as the display area A ofthe flexible substrate 420A, no image is visible on the peripheralcircuit area B of the flexible substrate 420A. Therefore, aconfiguration of covering the peripheral circuit area B of the flexiblesubstrate 420A should be present as a separate protective member thatmay be positioned on the flexible substrate 420A, which results inrestriction on design of the flexible display device and can beaesthetically unpleasing to consumers. Accordingly, it is advantageousto decrease the bezel area by bending the peripheral circuit area B ofthe flexible substrate 420A toward a rear or lateral surface of theflexible substrate 420A. However, the support film 410A has a largerthickness than the flexible substrate 420A. Therefore, when the supportfilm 410A is bent, an elastic restoring force may be generated, makingit difficult to maintain a bent shape of the support film 410A.Alternatively or in addition, a configuration of the display unit 430Aor the polarizer that may be disposed on the flexible substrate 420A maybe peeled off in a bent state. In the flexible display device 400Aaccording to one embodiment of the present invention, the pattern 411Afor facilitating the bending may be formed in an area of the supportfilm 410A corresponding to the third area C of the flexible substrate420A to minimize an elastic restoring force of the support film 410A. Asa result, it is possible to facilitate the bending of the flexiblesubstrate 420A, improve peeling of the elements formed on the flexiblesubstrate 420A, and provide a more improved design.

FIG. 4C is a cross-sectional view of a flexible display device accordingto still another embodiment. Referring to FIG. 4C, a flexible displaydevice 400B includes a support film 410B, a flexible substrate 420B, adisplay unit 430B, a polarizer 450B, a wire 465B, a drive circuit unit470B and an organic film 480B. The support film 410B, the flexiblesubstrate 420B, the display unit 430B, the wire 465B and the drivecircuit unit 470B are substantially identical to the support film 110,the flexible substrate 120, the display unit 130, the wire 165 and thedrive circuit unit 170 shown in FIG. 1B, and the polarizer 450B issubstantially identical to the polarizer 450A shown in FIG. 4A, and thusrepeated description of the above-described elements is omitted hereinfor the sake of brevity.

The drive circuit unit 470B configured to transfer various signals tothe display unit 430B from the outside, and the wire 465B configured toprovide electrical connection between the display unit 430B and thedrive circuit unit 470B are formed. The wire 465B is electricallyconnected with a wire 471B of the drive circuit unit 470B. When flexiblesubstrate 420B having the display unit 430B, the wire 465B and a padportion 472B formed therein is bent, strain is caused in the displayunit 430B and the wire 465B formed on the flexible substrate 420B. Inthe flexible display device 400B of FIG. 4B, however, the organic film480B is formed on the wire 465B such that the flexible display substrate420B and the wire 465B is positioned substantially in the neutral planewithin the flexible display device 400. When the flexible display device400B is bent, the tensile force from the support film 410B and thecompressive force from the organic film 480B may be simultaneouslyapplied to flexible display substrate 420B and the wire 465B so that themechanical stress can be neutralized. Thus the wire 465B may be in astress-free state so that the flexible substrate 420B and the wire 465Bcan be protected from mechanical stress caused from bending of theflexible display device 400B. Here, to offset the tensile force and thecompressive force applied respectively to the flexible substrate 420Band the wire 465B, the organic film 480B may have the same or greaterthickness than the support film 410B.

The organic film 480B is formed at a space between the display unit 430Band the drive circuit unit 470B. As described above, a pattern 411B isformed in an area corresponding to the third area C of the flexiblesubstrate 420B, and the flexible display device 400B is bent withrespect to the third area C of the flexible substrate 420B. As a result,an area in which the highest strain is formed at the third area C of theflexible substrate 420B. Therefore, it is preferred that the organicfilm 480B is formed to cover the third area C of the flexible substrate420B. In some embodiments, when the space between the display unit 430Band the drive circuit unit 470B corresponds to a part of a second areaand the third area C of the flexible substrate 420B as shown in FIG. 4C,the organic film 480B is formed on a part of the peripheral circuit areaB as well as the third area C of the flexible substrate 420B.

Since the flexible substrate 420B is flexible, the display area of theflexible display device 400B may also be bent in addition to the thirdarea C. In such cases, the organic film 480B may be disposed on thedisplay area A as well as the third area C of the flexible substrate420B so as to configure the areas to be the neutral plane within theflexible display device 400B is bent as a whole.

FIG. 4D is a cross-sectional view of a flexible display device accordingto yet another embodiment. FIG. 4E is a cross-sectional view showing abent state of the flexible display device shown in FIG. 4D. The elementsshown in FIGS. 4A and 4D are substantially identical to each other whenthe elements have the same numerals other than the alphabet charactersin the corresponding reference numerals, and thus repeated descriptionof the elements is omitted herein for the sake of brevity.

A flexible substrate 420C includes a display area A, a peripheralcircuit area B, a third area C, a fourth area D and a fifth area E. Thedisplay area A of the flexible substrate 420A refers to a display area,that is, an area on which an image is actually displayed. The peripheralcircuit area B, the third area C, the fourth area D and the fifth area Eof the flexible substrate 420C refer to non-display areas, that is,areas on which no image is displayed. The display area A, the peripheralcircuit area B and the third area C of the flexible substrate 420C aresubstantially identical to the display area A, the peripheral circuitarea B and the third area C of the flexible substrate 420A shown in FIG.4A, and thus repeated description of the display area A, the peripheralcircuit area B and the third area C of the flexible substrate 420C isomitted herein for the sake of brevity.

The fifth area E of the flexible substrate 420C is a non-display areawhich is positioned at the outermost area of the flexible substrate420C. Since the fifth area E of the flexible substrate 420C ispositioned at an edge portion of the flexible substrate 420C, the secondarea E of the flexible substrate 420C may also be referred to as an edgearea or a bezel area.

The fourth area D of the flexible substrate 420C is a non-display areawhich is positioned between the third area C and the fifth area E of theflexible substrate 420C. Also, since the fourth area D of the flexiblesubstrate 420C is positioned at a peripheral portion of the display areaA of the flexible substrate 420C, and positioned between the displayarea A and the fifth area E of the flexible substrate 420C, the fourtharea D of the flexible substrate 420C may be referred to as a peripheralarea, a middle area or a bezel area.

A support film 410C is disposed to come in contact with the flexiblesubstrate 420C. One surface of the flexible substrate 420C on which adisplay unit 430C is disposed is a top or front surface of the flexiblesubstrate 420C while the other surface of the flexible substrate 420Cwith which the support film 410C comes in contact may be referred to asa bottom or rear surface of the flexible substrate 420C.

The support film 410C includes a bending pattern 411C for facilitatingbending of the support film 410C. As a result, bending of variouselements included in the flexible display device 400C may also befacilitated by facilitating the bending of the support film 410C. Thepattern 411C for facilitating the bending may also be referred to as aneasily crookable shape, an easily bendable shape, a bendable print, or abending line.

The pattern 411C for facilitating the bending includes a pattern 411C1for facilitating primary bending and a pattern 411C2 for facilitatingsecondary bending. The bending pattern 411C1 for facilitating theprimary bending and the bending pattern 411C2 for facilitating thesecondary bending may be formed in areas of the support film 410Ccorresponding to the third area C and the fourth area D of the flexiblesubstrate 420C, respectively. The bending pattern 411C1 for facilitatingthe primary bending and the bending pattern 411C2 for facilitating thesecondary bending may be formed with the same shape and size, or formedwith different shapes and sizes.

FIG. 4F is a cross-sectional view of a flexible display device accordingto an embodiment of the present invention. FIG. 4G is a cross-sectionalview showing a bent state of the flexible display device shown in FIG.4F. The elements shown in FIGS. 4D and 4F are substantially identical toeach other when the elements have the same numerals except for theletters in the corresponding reference numerals, and thus repeateddescription of the elements is omitted herein for the sake of brevity.

A display unit 430D may include a first display unit 431D and a seconddisplay unit 432D. The first display unit 431D may be formed at a firstarea A of a flexible substrate 420D, and the second display unit 432Dmay be formed at a second area B of the flexible substrate 420D. As thedisplay unit 430D is divided into the first display unit 431D and thesecond display unit 432D. In some embodiments, the first display unit431D and the second display unit 432D are configured to operateindependently from one another. That is, the first display unit 431D andthe second display unit 432D may be configured to receive control signalfrom a different source (e.g., distinct GIP, distinct content source,distinct drive IC, etc). As such, one display unit may be turned offwhile the other display unit is displaying image. Also, one display unitmay play content from a first input device while the other display unitplays content from a second input device.

When a support film 410D and the flexible substrate 420D are bent withrespect to a third area C of the flexible substrate 420D, the seconddisplay unit 432D may display an image on a lateral or rear surface of aflexible display device 400D. In some embodiments, the display unit 430Dmay further include a third display unit. Here, the third display unitmay be formed at a fifth area E of the flexible substrate 420D toindependently display an image.

A polarizer 450D is formed on the first area A, the second area B andthe third area C of the flexible substrate 420D. In the case where thedisplay unit 430D is an organic light emitting diode, a contrast ratiois markedly degraded when an external light incident from the outside isreflected on a metal electrode or a wire of the organic light emittingdiode. In the flexible display device 400D according to still anotherembodiment of the present invention, since the display unit 430D isformed on the first area A and the second area B of the flexiblesubstrate 420D, degradation of the contrast ratio caused by reflectionof external light may be prevented by disposing the polarizer 450D onthe first area A, the second area B, and the third area C between thesecond area B and the first area A of the flexible substrate 420D. Also,since the polarizer 450D is formed on the first area A, the second areaB and the third area C of the flexible substrate 420D, the polarizer450D may be curved with respect to the third area C of the flexiblesubstrate 420D as the flexible display device 400D is bent.

FIG. 5A is a top view of a support film used to illustrate the flexibledisplay device according to another embodiment. FIG. 5B is across-sectional view of the flexible display device taken along lineVb-Vb′ of FIG. 5A. Referring to FIGS. 5A and 5B, a flexible displaydevice 500 includes a flexible substrate 520, a display unit 530 and asupport film 510. Among the elements of the flexible display device 500,only the support film 510 is shown in FIG. 5A for the sake ofconvenience of description. The flexible substrate 520 and the displayunit 530 are substantially identical to the flexible substrate 220B andthe display unit 230B shown in FIGS. 2E and 2F, and thus repeateddescription of the flexible substrate 520 and the display unit 530 isomitted herein for the sake of brevity.

The support film 510 includes a first support film 515 and a secondsupport film 516. The first support film 515 is disposed on a rearsurface of the first area A, and the second support film(s) 516 isdisposed the rear surface of the second area(s) B of the flexiblesubstrate 520. The first support film 515 and the second support film(s)516 are spaced apart from each other with a gap formed between the firstsupport film 515 and the second support film(s) 516. Since there is thegap formed between the first support film 515 and the second supportfilm 516 the elastic restoring force of the support film 510, as awhole, is reduced. Accordingly, bending of the flexible substrate 520can be localized around the gap and thereby prevent or reduce thepeeling of the elements formed on the flexible substrate 520.

In some embodiments, the gap between the first support film 515 and thesecond support film 516 may be filled with a resin material (e.g.,sealant, thermosetting resin) to protect the components on the flexiblesubstrate 520 from the external environments such as moisture or oxygen.The resin material, when filled and cured in the gap, should be lessrigidity than the support films adhered on other parts of the displaydevice.

In some embodiments, a side end of first support film 515 and a side endof the second support film 516 are not perpendicular to thecorresponding portion of the flexible display substrate, but are angledso that the gap between the two adjacent support films 515 and 516 isreduced upon bending of the flexible substrate 520. This way, the resinmaterial for filling the gap can be wholly eliminated or at leastreduced in the flexible display device.

FIG. 6 is a flowchart illustrating a method of manufacturing a flexibledisplay device according to another embodiment. FIGS. 7A to 7D arecross-sectional views illustrating respective processes of a method ofmanufacturing an organic light emitting display device according to oneembodiment.

First, a display unit is formed on a flexible substrate (S60). Formingthe display unit on the flexible substrate will be described in furtherdetail with reference to FIG. 7A.

Referring to FIG. 7A, forming a display unit 730 on a flexible substrate720 may include directly forming a display element on the flexiblesubstrate 720, or disposing an externally formed display element on theflexible substrate 720. Forming the display unit 730 on the flexiblesubstrate 720 may include forming the display unit 730 on a display areaA of the flexible substrate 720. It is assumed herein that the displayunit 730 is an organic light emitting diode for the sake of convenienceof description, but the present invention is not limited thereto. Forexample, various other display elements may be used herein. Forming anorganic light emitting diode as the display unit 730 may be performedusing various known methods. Next, a support film is disposed on a rearsurface of the flexible substrate (S61), and a polarizer is disposed ona top surface of the flexible substrate (S62). Disposing the supportfilm on the rear surface of the flexible substrate and disposing thepolarizer on the top surface of the flexible substrate will be describedin further detail with reference to FIG. 7B.

Referring to FIG. 7B, disposing a polarizer 750 on a top surface of theflexible substrate 720 may include disposing the polarizer 750 on thedisplay unit 730 disposed on the display area A of the flexiblesubstrate 720.

Referring to FIG. 7C, the support film 710 may be disposed to come incontact with the flexible substrate 720. The support film 710 is anelement configured to support the flexible substrate 720, and thus maybe disposed at a rear surface of the flexible substrate 720.

FIGS. 6 and 7A to 7C show that the polarizer 750 is disposed on theflexible substrate 720, and the support film 710 is then disposed on theflexible substrate 720, but the present invention is not limitedthereto. For example, the support film 710 may be disposed on theflexible substrate 720, and the polarizer 750 may then be disposed onthe flexible substrate 720.

Subsequently, a cover is disposed on the polarizer (S63). Disposing thecover is substantially identical to the process of disposing the covershown in FIG. 1I, and thus repeated description of such a process isomitted for brevity.

A pattern for facilitating bending is formed in at least one of thesupport film 710, the polarizer 750 and a cover 740. For the sake ofconvenience of description, FIGS. 7A to 7C show that the pattern 711 isformed only in the support film 710 among the support film 710, thepolarizer 750 and the cover 740, but the present invention is notlimited thereto. For example, the pattern may be formed in at least oneof the support film 710, the polarizer 750 and the cover 740. Formingthe pattern for facilitating the bending in at least one of the supportfilm 710, the polarizer 750 and the cover 740 may include forming thepattern in at least one of the support film 710, the polarizer 750 andthe cover 740 using a laser process as well as a mechanical process suchas a piercing process, a punching process, a press process, ahalf-cutting process, etc. The pattern for facilitating the bending issubstantially identical to the pattern for facilitating the bendingshown in FIGS. 1 through 5, and thus repeated description of the patternfor facilitating the bending is omitted for brevity.

According to the embodiments of the present invention, the flexibledisplay device and the method of manufacturing the same have at leastthe following effects. The flexible display device capable of realizinga narrow bezel-type or bezel-free display device and also enablesimproved types of design and improved method of manufacturing theflexible display device. Also, narrow bezel-type or bezel-free displaydevice can be embodied by facilitating bending of a bezel area of theflexible display device. Further, damage to the bending area can bereduced.

It will be apparent to those skilled in the art that variousmodifications can be made to the above-described embodiments of thepresent invention without departing from the scope of the invention.Thus, it is intended that the present invention covers all suchmodifications provided they come within the scope of the appended claimsand their equivalents.

What is claimed is:
 1. A flexible display device, comprising: a flexibledisplay substrate comprising: a display area formed with pixel elementsfor generating an image, and a peripheral circuit area adjacent to thedisplay area, the peripheral circuit area comprising components totransmit signals to the pixel elements in the display area; and asupport substrate attached to the flexible display substrate to providerigidity to the flexible display device, the support substratecomprising: a non-bending area, and a bending area extending along aboundary of the display area and the peripheral circuit area, thebending area adjacent to the non-bending area, the bending area havingless rigidity than the non-bending area.
 2. The flexible display deviceof claim 1, wherein thin film transistors are formed as the pixelelements on the flexible display substrate, the thin film transistorsoperating light emitting elements formed on the flexible displaysubstrate based on the transmitted signals.
 3. The flexible displaydevice of claim 1, wherein the bending area includes a bending patternformed with a plurality of holes, a slit extending across the bendingarea or a half-cut channel.
 4. The flexible display device of claim 3,wherein the half-cut channel is a hollow channel with an opening facingtowards the flexible display substrate or facing away from the flexibledisplay substrate.
 5. The flexible display device of claim 1, furthercomprising a cover glass having a display region corresponding to thedisplay area of the flexible display substrate.
 6. The flexible displaydevice of claim 1, wherein the flexible display substrate is bent at asubstantially right angle along the bending area.
 7. The flexibledisplay device of claim 1, further comprising a polarizer on theflexible display substrate, the polarizer formed with a bending patternalong the bending area of the support substrate to provide flexibilityto the polarizer in the bending area.
 8. The flexible display device ofclaim 1, further comprising a metal substrate interposed between theflexible display substrate and the support substrate.
 9. The flexibledisplay device of claim 1, further comprising an encapsulation layerextending over at least a portion of the display area and at least aportion of the peripheral circuit area.
 10. The flexible display deviceof claim 1, further comprising an organic film on the components fortransmitting the signals in the peripheral circuit area to reducetensile stress in the components when bending occurs in the bendingarea.
 11. A flexible display device, comprising: a flexible displaysubstrate having a display area and a peripheral circuit area, thedisplay area juxtaposed to a peripheral circuit area; and a supportsubstrate disposed on the flexible display substrate, the supportsubstrate having a bending pattern to provide flexibility at a bendingarea of the support substrate and to reduce resilient force of theflexible display device, wherein the bending area corresponds to aboundary between the display area and the peripheral circuit area of theflexible display substrate.
 12. The flexible display device of claim 11,wherein the bending pattern is a plurality of holes spaced apart fromeach other by a predetermined distance.
 13. The flexible display deviceof claim 11, wherein a bending angle between the display area and theperipheral circuit area is between 70 degrees and 110 degrees.
 14. Aflexible display device comprising: a multi-layered substrate structureincluding: a first flexible substrate having at least one display area,and a second flexible substrate fixed to the first flexible substrateand more rigid than the first flexible substrate, the second flexiblesubstrate formed with a bending pattern to define a bending area alongwhich the multi-layered substrate structure is bent; and an organiclight emitting element on the first flexible substrate of themulti-layered substrate structure.
 15. The flexible display device ofclaim 14, wherein the bending pattern is formed along a boundary betweenthe display area and a peripheral circuit area of the multi-layeredsubstrate structure.
 16. The flexible display device of claim 15,wherein the bending pattern includes a plurality of holes aligned alongthe boundary between said at least one display area and the peripheralcircuit area of the multi-layered substrate structure.
 17. The flexibledisplay device of claim 14, wherein the multi-layered substratestructure includes at least two bending patterns arranged at one or moreend portions of the second flexible substrate.
 18. The flexible displaydevice of claim 14, wherein the first flexible substrate structurecomprises a plurality of display areas, and wherein the bending patternis formed in a boundary of the at least two adjacent display areas. 19.The flexible display device of claim 14, wherein the second flexiblesubstrate includes at least two separated bending patterns, and whereinsaid at least one display area is placed between said at least twoseparated bending patterns.
 20. The flexible display device of claim 14,wherein the bending pattern includes a half-cut channel on one surfaceof the second flexible substrate facing the first flexible substrate orfacing away from the first flexible substrate.
 21. The flexible displaydevice of claim 14, wherein the multi-layered substrate structure isbent at a substantially right angle along the bending area.
 22. Aflexible display device, comprising: a flexible display substratecomprising a plurality of display areas, each of the display areasformed with pixel elements for generating an image; and a plurality ofsupport substrates more rigid than the flexible display substrate, eachof the support substrate fixed to a selected portion of the flexibledisplay substrate to maintain the selected portion of the flexiblesubstrate in a planar shape, the flexible display substrate bent at abending area not fixed with the at least one support substrates.
 23. Theflexible display device of claim 22, wherein the plurality of supportsubstrates include at least two adjacent support substrates, each of thetwo adjacent support substrate having a side end facing the side end ofthe other adjacent support substrate, and wherein the side ends of saidat least two adjacent support substrate are angled relative to thesurface of the respective support substrate fixed to the selectedportion of the flexible display substrate.
 24. The flexible displaydevice of claim 22, wherein the selected portion corresponds to one ofthe display areas of the flexible display substrate and the bending areaincludes a peripheral circuit area for transmitting signals to the oneof the display areas.
 25. The flexible display device of claim 22,wherein the flexible substrate comprises a first portion fixed with afirst support substrate, a second portion fixed with a second supportsubstrate, and a third portion fixed with a third support substrate,wherein a first bending portion is formed between the first portion andthe second portion, and a second bending portion is formed between thesecond portion and the third portion.